Health related quality of life is improved by botulinum neurotoxin type A in long term treated patients with focal dystonia.
(33/694)
OBJECTIVES: The advent of botulinum neurotoxin type A (BoNT/A) gave rise to substantial progress in the treatment of focal dystonias. In the light of the high costs of the toxin and the necessity to establish valid outcome indices for this treatment apart from sheer reduction of dystonic muscle tone and posture, the impact of focal dystonia and its treatment with BoNT/A on patients' health related quality of life (HRQL) was determined. METHODS: Fifty patients with cranial and cervical dystonia treated long term with BoNT/A were enrolled in a prospective, open labelled cohort study. The HRQL was assessed using the EuroQol (EQ-5D) and the short form 36 health survey questionnaire (SF-36) at baseline before BoNT/A injections and at two follow up visits after 6 and 12 weeks covering one BoNT/A treatment period with maximum effect size at the first follow up. RESULTS: Compared with a general population sample, a considerable negative impact of focal dystonia on HRQL was found in patients under investigation. In both disease types, BoNT/A treatment led to a significant improvement in several HRQL dimensions, in particular providing moderate to marked effect sizes in the fields of mental health and pain. The impairment of HRQL due to pain as well as the BoNT/A induced improvement within this SF-36 subscore were significantly higher in patients with cervical dystonia. Under BoNT/A therapy, no correlation was found between changes of clinical outcome scores and HRQL measures. CONCLUSIONS: The data confirm that BoNT/A is able to induce a significant, but temporary amelioration of several aspects of HRQL in both types of focal dystonia. This may substantially contribute to the patients' subjective benefit from the therapy. Moreover, the data provide further arguments to accept high costs of the BoNT/A treatment in these severely handicapped patients, as a consequence of its considerable benefit on quality of life. (+info)
Regulation of neuronal NMDA receptors (NMDARs) by group I metabotropic glutamate receptors (mGluRs) is known to play a critical role in synaptic transmission. The molecular mechanisms underlying mGluR1-mediated potentiation of NMDARs are as yet unclear. The present study shows that in Xenopus oocytes expressing recombinant receptors, activation of mGluR1 potentiates NMDA channel activity by recruitment of new channels to the plasma membrane via regulated exocytosis. Activation of mGluR1alpha induced (1) an increase in channel number times channel open probability, with no change in mean open time, unitary conductance, or reversal potential; (2) an increase in charge transfer in the presence of NMDA and the open channel blocker MK-801, indicating an increased number of functional NMDARs in the cell membrane; and (3) increased NR1 surface expression, as indicated by cell surface Western blots and immunofluorescence. Botulinum neurotoxin A or expression of a dominant negative mutant of synaptosomal associated protein of 25 kDa molelcular mass (SNAP-25) greatly reduced mGluR1alpha-mediated potentiation, indicating that receptor trafficking occurs via a SNAP-25-mediated form of soluble N-ethylmaleimide sensitive fusion protein attachment protein receptor-dependent exocytosis. Because group I mGluRs are localized to the perisynaptic region in juxtaposition to synaptic NMDARs at glutamatergic synapses in the hippocampus, mGluR-mediated insertion of NMDARs may play a role in synaptic transmission and plasticity, including long-term potentiation. (+info)
Candidate vaccine against botulinum neurotoxin serotype A derived from a Venezuelan equine encephalitis virus vector system.
(35/694)
A candidate vaccine against botulinum neurotoxin serotype A (BoNT/A) was developed by using a Venezuelan equine encephalitis (VEE) virus replicon vector. This vaccine vector is composed of a self-replicating RNA containing all of the VEE nonstructural genes and cis-acting elements and also a heterologous immunogen gene placed downstream of the subgenomic 26S promoter in place of the viral structural genes. In this study, the nontoxic 50-kDa carboxy-terminal fragment (H(C)) of the BoNT/A heavy chain was cloned into the replicon vector (H(C)-replicon). Cotransfection of BHK cells in vitro with the H(C)-replicon and two helper RNA molecules, the latter encoding all of the VEE structural proteins, resulted in the assembly and release of propagation-deficient, H(C) VEE replicon particles (H(C)-VRP). Cells infected with H(C)-VRP efficiently expressed this protein when analyzed by either immunofluorescence or by Western blot. To evaluate the immunogenicity of H(C)-VRP, mice were vaccinated with various doses of H(C)-VRP at different intervals. Mice inoculated subcutaneously with H(C)-VRP were protected from an intraperitoneal challenge of up to 100,000 50% lethal dose units of BoNT/A. Protection correlated directly with serum enzyme-linked immunosorbent assay titers to BoNT/A. The duration of the immunity achieved was tested at 6 months and at 1 year postvaccination, and mice challenged at these times remained refractory to challenge with BoNT/A. (+info)
Ca(2+) influx and cAMP elevation overcame botulinum toxin A but not tetanus toxin inhibition of insulin exocytosis.
(36/694)
Previous reports showed that cleavage of vesicle-associated membrane protein-2 (VAMP-2) and synaptosomal-associated protein of 25 kDa (SNAP-25) by clostridial neurotoxins in permeabilized insulin-secreting beta-cells inhibited Ca(2+)-evoked insulin secretion. In these reports, the soluble N-ethylmaleimide-sensitive factor attachment protein target receptor proteins might have formed complexes, which preclude full accessibility of the putative sites for neurotoxin cleavage. In this work, VAMP-2 and SNAP-25 were effectively cleaved before they formed toxin-insensitive complexes by transient transfection of insulinoma HIT or INS-1 cells with tetanus toxin (TeTx) or botulinum neurotoxin A (BoNT/A), as shown by immunoblotting and immunofluorescence microscopy. This resulted in an inhibition of Ca(2+) (glucose or KCl)-evoked insulin release proportionate to the transfection efficiency (40-50%) and an accumulation of insulin granules. With the use of patch-clamp capacitance measurements, Ca(2+)-evoked exocytosis by membrane depolarization to -10 mV was abolished by TeTx (6% of control) but only moderately inhibited by BoNT/A (30% of control). Depolarization to 0 mV to maximize Ca(2+) influx partially overcame BoNT/A (50% of control) but not TeTx inhibition. Of note, cAMP activation potentiated Ca(2+)-evoked secretion by 129% in control cells but only 55% in BoNT/A-transfected cells and had negligible effects in TeTx-transfected cells. These results indicate that, whereas VAMP-2 is absolutely necessary for insulin exocytosis, the effects of SNAP-25 depletion on exocytosis, perhaps on insulin granule pool priming or mobilization steps, could be partially reversed by higher levels of Ca(2+) or cAMP potentiation. (+info)
Epitope mapping of neutralizing botulinum neurotoxin A antibodies by phage display.
(37/694)
Single-chain antibodies neutralize activity and bind nonoverlapping epitopes of botulinum A neurotoxin. Two phage display epitope libraries were constructed from the 1.3 kb of binding domain cDNA. The minimal epitopes selected against the single-chain Fv-Fc antibodies correspond to conformational epitopes with amino acid residues 1115 to 1223 (S25), 1131 to 1264 (3D12), and 889 to 1294 (C25). (+info)
Botulinum toxin type A in treatment of bilateral primary axillary hyperhidrosis: randomised, parallel group, double blind, placebo controlled trial.
(38/694)
OBJECTIVES: To evaluate the safety and efficacy of botulinum toxin type A in the treatment of bilateral primary axillary hyperhidrosis. DESIGN: Multicentre, randomised, parallel group, placebo controlled trial. SETTING: 17 dermatology and neurology clinics in Belgium, Germany, Switzerland, and the United Kingdom. PARTICIPANTS: Patients aged 18-75 years with bilateral primary axillary hyperhidrosis sufficient to interfere with daily living. 465 were screened, 320 randomised, and 307 completed the study. INTERVENTIONS: Patients received either botulinum toxin type A (Botox) 50 U per axilla or placebo by 10-15 intradermal injections evenly distributed within the hyperhydrotic area of each axilla, defined by Minor's iodine starch test. MAIN OUTCOME MEASURES: Percentage of responders (patients with >/=50% reduction from baseline of spontaneous axillary sweat production) at four weeks, patients' global assessment of treatment satisfaction score, and adverse events. RESULTS: At four weeks, 94% (227) of the botulinum toxin type A group had responded compared with 36% (28) of the placebo group. By week 16, response rates were 82% (198) and 21% (16), respectively. The results for all other measures of efficacy were significantly better in the botulinum toxin group than the placebo group. Significantly higher patient satisfaction was reported in the botulinum toxin type A group than the placebo group (3.3 v 0.8, P<0.001 at 4 weeks). Adverse events were reported by only 27 patients (11%) in the botulinum toxin group and four (5%) in the placebo group (P>0.05). CONCLUSION: Botulinum toxin type A is a safe and effective treatment for primary axillary hyperhidrosis and produces high levels of patient satisfaction. (+info)
Social phobia in spasmodic torticollis.
(39/694)
OBJECTIVES: To study the prevalence of psychiatric comorbidity assessed by the use of a structured clinical interview in a large, representative sample of patients with spasmodic torticollis (ST) and to test the hypothesis that social phobia would be highly prevalent. METHODS: In a consecutive cohort of 116 patients with ST treated with botulinum toxin overall psychiatric comorbidity was studied prospectively with the structured clinical interview (SCID) for DSM-IV axis I disorders. Physical disability and psychosocial variables were also assessed with standardised self rating questionnaires. RESULTS: 41.3% of the subjects met DSM-IV clinical criteria A-G for current social phobia as the primary psychiatric diagnosis. This figure rose to 56% including secondary and tertiary psychiatric diagnosis. There was no correlation between severity of disease (Tsui score, severity of pain, body image dissatisfaction score) and psychiatric comorbidity. The only significant predictor of psychiatric comorbidity was depressive coping behaviour (logistic regression analysis, p < 0.01; OR=10.8). Compared with a representative sample of the general adult population, in the patients with ST the prevalence of clinically relevant social phobia is 10-fold, of mood disorders 2.4-fold, and of lifetime psychiatric comorbidity 2.6-fold increased. CONCLUSIONS: A particularly high prevalence of social phobia was found in the cohort of patients with ST. The finding of a high prevalence of social phobia and depressive coping behaviour as the main predictor of psychiatric comorbidity may make a subgroup of patients with ST particularly amenable to specific psychotherapeutic interventions. (+info)
Differential inhibition by botulinum neurotoxin A of cotransmitters released from autonomic vasodilator neurons.
(40/694)
The role of the soluble NSF attachment protein receptor (SNARE) protein complex in release of multiple cotransmitters from autonomic vasodilator neurons was examined in isolated segments of guinea pig uterine arteries treated with botulinum neurotoxin A (BoNTA; 50 nM). Western blotting of protein extracts from uterine arteries demonstrated partial cleavage of synaptosomal-associated protein of 25 kDa (SNAP-25) to a NH2-terminal fragment of approximately 24 kDa by BoNTA. BoNTA reduced the amplitude (by 70-80%) of isometric contractions of arteries in response to repeated electrical stimulation of sympathetic axons at 1 or 10 Hz. The amplitude of neurogenic relaxations mediated by neuronal nitric oxide (NO) was not affected by BoNTA, whereas the duration of peptide-mediated neurogenic relaxations to stimulation at 10 Hz was reduced (67% reduction in integrated responses). In contrast, presynaptic cholinergic inhibition of neurogenic relaxations was abolished by BoNTA. These results demonstrate that the SNARE complex has differential involvement in release of cotransmitters from the same autonomic neurons: NO release is not dependent on synaptic vesicle exocytosis, acetylcholine release from small vesicles is highly dependent on the SNARE complex, and neuropeptide release from large vesicles involves SNARE proteins that may interact differently with regulatory factors such as calcium. (+info)